Corrosion resistant apparatus for conversion coating of metals

Claim 1

IN AN APPARATUS SUITABLE FOR THE PHOSPHATIZING OF METALS WITH A TREATING SOLUTION COMPRISING A VOLATILE CHLOROHYDROCARBON SOLVENT CONTAINING AT LEAST TWO CARBON ATOMS AND PHOSPHORIC ACID, SAID APPARATUS COMPRISING A TREATING VESSEL EQUIPPED WITH HEATING MEANS ADAPTED TO BOIL SAID TREATING SOLUTION, COOLING MEANS ADAPTED FOR CONTROLLING THE VAPOR LEVEL ABOVE AND SAID SOLUTION BY VAPOR CONDENSATION, A TROUGH ADAPTED FOR COLLECTING CONDENSATE BELOW SAID COOLING MEANS AND CONDUIT MEANS FOR REMOVING CONDENSATE FROM SAID TROUGH, THE IMPROVEMENT WHEREIN ALL PORTIONS OF SAID APPARATUS ADAPTED FOR EXPOSURE TO CONDENSING VAPOR AND CONDENSATE PRESENT A SURFACE OF NICKEL ALLOY CONSISTING ESSENTIALLY OF, BY WEIGHT, 45 TO 65% NICKEL, 3 TO 25% IRON, 25 TO 40% OF A METAL SELECTED FROM THE GROUP CONSISTING OF CHROMIUM, MOLYBDENUM, TUNGSTEN AND MIXTURES THEREOF, UP TO 5% COBALT, UP TO 1% MANGANESE AND UP TO 1% SILICON, ALL OF SAID NAMED ALLOY INGREDIENTS MAKING UP A TOTAL OF APPROXIMATELY 100%, THE REMAINDER OF SAID APPARATUS BEING CONSTRUCTED OF METALS SELECTED FROM THE GROUP CONSISTING ESSENTIALLY OF IRON, STEEL, AND STAINLESS CONTAINING AT LEAST 60% IRON.